Planet Hunter: Geoff Marcy and the Search for Other Earths
Jason Mcllroy operates the telescope at the summit Mcllroy and Marcy can see each other by video as they work Marcy is shown in the monitor above Mcllroy's desk Planet Hunter Paul Butler
J Dr Paul Butler hunted planets with Geoff Marcy for years With their team they found about half of the known extrasolar planets What I love about planet hunting are the challenges of improving the system Butler says I also love looking at the stars and knowing that many have planets that I have found I am especially proud of the fact that I have never made a false planet claim Butler figured out how to use iodine gas to sharpen measurements of star movement which made planet detection possible He also helped develop the computer software that analyzes the measurements and pinpoints wobbling stars Planet hunting groups across the world now use this detection system In late 2007 Butler and Dr Steven Vogt the designer and builder of the spectrometers at the Keck and Lick observatories formed their own planet search team I love the fact that with glass steel and silicon chips in effect rocks and sand we have put together a system that can find planets around stars that are light years away he says The time is almost 7 00 pm the beginning of
Marcy's block of time to use the telescope A long night of planet hunting stretches ahead He will finish at 5 30 in the morning For the next three days Marcy will sleep during the day play tennis late in the afternoon eat a quick dinner and then go to the telescope control room at 7 00 p m He keeps his fingers crossed that the good weather will hold Telescope time is costly and the instrument is sensitive When the weather is bad the telescope shuts down for the night Tonight Marcy is excited maybe he will find another distant planet orbiting a star like our Sun Maybe this time the planet will be similar to Earth the kind of planet most likely to sustain life Intelligent Life Beyond Our Solar System Marcy and his former co worker Dr Paul Butler are world leaders in planet hunting Since 1995 Marcy has helped detect 500 of the 900 planets found outside our solar system which are known as extrasolar planets As the team developed more and more precise search techniques Marcy came closer to his dream of finding a small rocky Earth like planet one that might harbor life In 2006 the team announced one of the smallest planets discovered at that time The planet which orbits the star Gliese 876 is seven to eight times more
massive than Earth The planet might seem large but most of the known extrasolar planets are even bigger They are about three hundred times more massive than Earth which puts them in a class with Jupiter and Saturn Other discoveries were equally thrilling In 2007 for the first time astronomers determined the composition of an extrasolar planet by figuring out the planet's density This planet which orbits the star Gliese 436 is made of rock and water similar to our Earth Later that year Marcy's team announced their finding of a fifth planet orbiting the star 55 Cancri the first discovery of five extrasolar planets orbiting one star The structure of this planetary system is close to that of our own solar system And new planetary systems are being discovered all the time by Marcy s team and by others In fact a planet hunting space telescope Kepler was launched in 2009 Kepler has found many new planets plus thousands of possible planets One new planet Kepler 22 b is the ideal distance from its Sun like star to have life In the telescope room Marcy adjusts the controls on one of the computers Surely in this huge universe there are other planets that have conditions ripe for life he says And how likely are they to have intelligent
